As taught in our copending application Ser. No. 619,526, significant advantages are achieved in photolithography when two-layer resists are used to produce a pattern on a suitable substrate in the fabrication of electronic devices or integrated circuitry on semiconductor chips. Depth of focus limitations are minimized by confining primary imaging to a positive photoresist which is uniformly applied as a thin film on top of a thick planarizing polymer layer, such as a polymethylmethacrylate. A suitable dye which absorbs in the active region of the thinly applied upper positive resist layer can be incorporated into the thicker PMMA planarizing base layer. The dye can absorb any stray light which might tend to reflect from the supporting substrate back to the thin upper positive resist layer interfering with a sharp resolution in the resulting portable conformable mask (PCM) obtained from the upper positive photoresist. Although improved results have been achieved with the two-layer photoresist procedure as shown by Chen et al., U.S. Pat. No. 4,362,809, variations in the profiles and thickness of the upper resist pattern can reduce its effectiveness as a mask during deep UV exposure of the lower resist layer. Rounded contours and lack of uniformity in the thickness of the final vertical resist profiles often can result.